How does the role of advertising differ in industrial and consumer advertising?

What is the role of advertising?
What is the role of industrial advertising?
What is the role of consumer advertising?
How do they both differ?

THIS IS NOT A CATCH-ALL ANSWER, MERELY A GUIDELINE
1. to inform, create interest and to ultimately induce a consumer to finalize a pruchase decision
2. among other things including all of the above, but the audience is highly specialized and holds prior knowledge of your product, concept, etc.
3. Consumer advertising focuses more on broadcasting a message to the widest audience posisble.
4. Audience is main difference, also the medium. Consumer will try to find a larger audience in an attempt to create sales via mass media. Industrial mostly focuses on smaller audience in advertisiments within specific trade magazines, locations, programs, etc.